U.S. patent application number 11/400408 was filed with the patent office on 2006-08-24 for recording apparatus having a device for detecting the presence or absence of a liquid.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Yoshio Uchikata.
Application Number | 20060187282 11/400408 |
Document ID | / |
Family ID | 16060933 |
Filed Date | 2006-08-24 |
United States Patent
Application |
20060187282 |
Kind Code |
A1 |
Uchikata; Yoshio |
August 24, 2006 |
Recording apparatus having a device for detecting the presence or
absence of a liquid
Abstract
A device for detecting the presence or absence of a liquid,
which is installed on an ink-jet recording apparatus, is configured
to determine the presence or absence of ink in the ink flow path by
detecting the reflection of light from a light transmission portion
by irradiating light thereon. The light transmission portion is
formed on at least a part of the ink path wall that forms the ink
flow path for supplying ink to the recording head. As a result, it
becomes possible for responding to consumer demands of designing a
smaller version of the ink tank, a cost effective production
thereof, and the like in addition to provide images with excellent
image qualities.
Inventors: |
Uchikata; Yoshio; (Yokohama,
JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
CANON KABUSHIKI KAISHA
TOKYO
JP
|
Family ID: |
16060933 |
Appl. No.: |
11/400408 |
Filed: |
April 10, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09452186 |
Dec 2, 1999 |
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11400408 |
Apr 10, 2006 |
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08678700 |
Jul 11, 1996 |
6024428 |
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09452186 |
Dec 2, 1999 |
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Current U.S.
Class: |
347/86 |
Current CPC
Class: |
B41J 2/17506 20130101;
B41J 2/17566 20130101; G01F 23/2922 20130101; B41J 2/17503
20130101; B41J 2/1752 20130101; B41J 2002/17573 20130101 |
Class at
Publication: |
347/086 |
International
Class: |
B41J 2/175 20060101
B41J002/175 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 14, 2005 |
JP |
1995-179156 |
Claims
1-20. (canceled)
21. An ink tank for supplying ink to a recording means that ejects
ink and is fixed on or removably mounted on a recording apparatus
for recording input image information on a recording medium using
the recording means, said ink tank comprising: a casing forming a
chamber for storing the ink, said casing having a plurality of
rectangular walls; an engagement member by which said ink tank
engages with the recording means, said engagement member being
provided on a first one of said walls; and a reflecting portion
having at least two surfaces configured to reflect an amount of
incident light from outside said ink tank according to an amount of
ink in said ink tank, said reflecting portion being arranged at a
predetermined position on a second one of said walls, wherein said
at least two surfaces are formed at predetermined angles with
respect to said second wall to form a dihedral angle having a
vertex line parallel to said second wall, said second wall is
different from said first wall, on which said engagement member is
provided, and said first wall shares a shorter edge of said second
wall as a border with said second wall.
22. An ink tank as claimed in claim 21, wherein the recording means
is an ink-jet recording head that uses an electrothermal transducer
for generating thermal energy required for allowing a phenomenon of
film boiling to appear in ink in order to eject ink therefrom.
23. A recording unit comprising an ink tank and a recording means
that ejects ink supplied by said ink tank, said recording means
being fixed on or removably mounted on a recording apparatus for
recording input image information on a recording medium using said
recording means, said ink tank comprising: a casing forming a
chamber for storing the ink, said casing having a plurality of
rectangular walls; an engagement member by which said ink tank
engages with the recording means, said engagement member being
provided on a first one of said walls; and a reflecting portion
having at least two surfaces configured to reflect an amount of
incident light from outside said ink tank according to an amount of
ink in said ink tank, said reflecting portion being arranged at a
predetermined position on a second one of said walls, wherein said
at least two surfaces are formed at predetermined angles with
respect to said second wall to form a dihedral angle having a
vertex line parallel to said second wall, said second wall is
different from said first wall, on which said engagement member is
provided, and said first wall shares a shorter edge of said second
wall as a border with said second wall.
24. A recording unit as claimed in claim 23, wherein said recording
means is an ink-jet recording head that uses an electrothermal
transducer for generating thermal energy required for allowing a
phenomenon of film boiling to appear in ink in order to eject ink
therefrom.
25. An ink tank as claimed in claim 21, wherein said reflecting
portion is located at a position offset from each of two parallel
edges of said second wall.
26. An ink tank as claimed in claim 21, wherein said reflecting
portion is located at a position offset from an imaginary line
connecting center points of two parallel edges of said second
wall.
27. An ink tank as claimed in claim 25, wherein said two parallel
edges of said second wall are parallel to the vertex line.
28. An ink tank as claimed in claim 25, wherein said two parallel
edges of said second wall are longer edges of said second wall.
29. An ink tank as claimed in claim 21, wherein each of said at
least two surfaces is rectangular, and longer edges of said at
least two surfaces are parallel to longer edges of said second
wall.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to an ink-jet recording
method, an ink-jet recording apparatus, an ink tank to be removably
mounted on such apparatus, and an ink-supplying means for supplying
ink to the ink tank, which make possible to obtain a high-quality
image on a recording medium. In addition, the present invention
also relates to recording systems including a copying machine, a
facsimile, and a printer, and also a word processor and a personal
computer integral with a recording device, and a recorded material
provided as a recording medium on which an image is recorded by the
recording apparatus.
RELATED ART
[0002] Heretofore, ink-jet recording apparatuses have been used as
output means on the commercial basis, for example they have been
used as printers as output means of recording systems such as
output devices of copying machines, facsimiles, electronic
typewriters, and word processors, output terminals of work
stations, and the like, and also such as handy- or portable-type
printers equipped in information-processing systems such as
personal computers and host computers, optical disk apparatuses,
video apparatuses, and so on. In these cases, each of the ink-jet
recording apparatuses is configured to meet a specific function, a
usage pattern, and the like of the corresponding apparatus.
[0003] As a general ink-jet recording apparatus, it has been known
that one comprises a recording device (recording head), an ink tank
for storing ink to be supplied to the head, a sheet-feed device for
feeding recording paper, and a control device to control these
devices. The recording head that discharges ink droplets from a
plurality of nozzles is serially moved or scanned in a direction
(main-scanning direction) perpendicular to a direction of feed
(sub-scanning direction). The ink-recording head performs a
recording movement, in which the recording paper is intermittently
fed a distance equal to the recorded width during non-recording
intervals. In the case of a configuration of the ink-jet recording
apparatus that uses an on-demand type recording head by which ink
is ejected onto the recording paper according to recording signals,
it has been widely used because of the advantages of low running
cost and quietness. In the case of a configuration of the ink-jet
recording apparatus that uses a full-line type recording head in
which a plurality of nozzles for ejecting ink is arranged linearly
in the sub-scanning direction, the recording head need only scan
the recording paper once to perform recording of a width
corresponding to the number of nozzles. This makes for increased
speed of recording operation.
[0004] By the way, a supply of ink becomes not good enough when the
remaining quantity of ink in an ink storage member such as the ink
tank described above is lower than a predetermined level. As a
consequence, a poor printed output may be obtained and so a
high-quality image formation becomes difficult. If it becomes empty
of ink perfectly, furthermore, an image cannot be formed on the
paper while ink-ejecting means of the recording head is driven in
spite of without containing ink. In this case, therefore, there is
the possibility of causing the failure of the ink-ejecting means.
Especially in the case of suing a heater for ejecting ink, as
described later, there is the possibility of destroying the whole
structure of the recording-head by an effect of abnormal heat-up.
Conventionally, therefore, an ink-jet recording apparatus having a
device for detecting the presence or absence of a liquid
(hereinafter, also referred as a liquid-detecting device), as shown
in FIG. 1.
[0005] The liquid-detecting device shown in FIG. 1 comprises a
cylindrical rod 1001, a light source 1003 connected with the rod
1001, and a light-receiving unit (i.e., a photosensor). In this
kind of the device configuration, the rod 1001 is in the type of
having light transmission properties and also having a tip portion
which is cut in a slanting direction. As shown in the figure, the
rod 1001 is arranged in an ink tank 1002. The light source 1003
emits light toward a bottom of the ink tank 1002 through the tip
portion of the rod 1001. In the case that the distance between the
tip portion of the rod 1001 and the bottom of the ink tank 1002 is
kept at a constant, the following conditions can be observed:
[0006] the condition that the tip portion of the rod 1001 is
immersed in ink I (e.g., ink level is indicated by a solid line A
higher than the tip portion);
[0007] the condition that there is a space between the tip portion
of the rod 1001 and ink level (e.g., ink level is indicated by a
solid line A' lower than the tip portion); and
[0008] the condition of empty out the ink tank 1002.
[0009] Under each of these conditions, reflected light having its
own refractive index can be detected. Therefore, through the use of
the differences in refractive indexes under the above conditions
the presence or absence of ink can be determined by detecting
whether the ink level is positioned between the tip portion of the
rod 1001 and the bottom of the ink tank 11002. Thus the photosensor
1004 receives the reflected light passing through the tip portion
of the rod 11001, and then the condition of the remaining quantity
of the ink is determined by the control unit 1005 connected with
the photosensor 1004. If the control unit 1005 makes a decision
that the remaining quantity of the ink is lower than the
predetermined quantity, the operator is instructed to change or
fill the ink tank by means of an indicator on an operation panel
(not shown) which is electrically connected to the control unit
1005.
[0010] However, in accordance with the conventional ink-detecting
method described above, light emitted from the light source 1004 is
reflected at an inner peripheral side wall of the rod 1001, so that
it is difficult to keep a constant incidence angle of reflected
light against a slant portion of the rod 1001 does not remain
constant. It results in the problem that the difference between the
strength of reflected light in the presence of ink and the strength
of reflected light in the absence of ink cannot be broadly-divided.
In addition, it also results in the problem that the device
configuration increases in complexity because of installing the rod
1001 in the ink tank (i.e., an ink-flow path of the ink tank).
Furthermore, it is difficult to respond to consumer demands, such
as for smaller and cheaper devices, to a sufficient degree because
of enlarged volume and limited shape of the ink tank as a result of
arranging the rod therein.
SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide an ink-jet
recording apparatus that performs a detection of the presence or
absence of ink at a low cost with reliability.
[0012] In a first aspect of the present invention, there is
provided a device for detecting the presence or absence of a
liquid, installed on an ink-jet recording apparatus on which a
recording head and an ink tank for supplying ink to the recording
head are fixed or removably mounted, comprising:
[0013] a light-emitting unit for emitting light to a light
transmitting portion having at least a part where a ridge portion
or groove portion in the shape of V in cross section are formed on
the ink tank;
[0014] a detecting unit for detecting light which is reflected off
the light transmitting portion; and
[0015] a means for transmitting the results obtained by the
detecting unit to a control unit of the ink-jet recording
apparatus.
[0016] In a second aspect of the present invention, there is
provided an ink tank for supplying an ink to a recording means,
which is fixed on or removably mounted on a recording apparatus for
recording an input image information on a recording medium by using
the recording means that ejects ink, comprising:
[0017] an ink-storing portion for storing ink, provided as an
ink-flow path for supplying ink to the recording means;
[0018] a front end portion on which an ink-supplying opening for
supplying the ink to the recording means;
[0019] a rear end portion formed on the other side of the ink tank
with respect to the front end portion;
[0020] a side surface portion on which a window portion made of a
light-transmitting material; and
[0021] other side source portions for surrounding the ink-storing
portion in conjunction with the side surface portion.
[0022] Here, the window portion may be formed by cutting at least a
part of the side surface portion into a groove portion in the shape
of V in cross section.
[0023] The window portion may be made of at least one ridge portion
in the shape of V in cross section.
[0024] In a third aspect of the present invention, there is
provided a recording apparatus for recording an input image
information on a recording medium by using a recording means for
ejecting ink, comprising:
[0025] a carriage on which an ink tank having a window portion of a
light-transmitting material on at least one side surface thereof is
fixed or removably mounted;
[0026] a device for detecting the presence or absence of a liquid,
which are arranged in a position facing to the window portion of
the ink tank mounted on the carriage; and
[0027] a control unit for determining the presence or absence of
ink in accordance with the results obtained by the device for
detecting the presence or absence of a liquid.
[0028] Here, the device for detecting the presence or absence of a
liquid may comprise a light-emitting unit and a light-receiving
unit.
[0029] The window portion may be formed by cutting at least a part
of the side surface portion into a groove portion in the shape of V
in cross section.
[0030] The window portion may be made of at least one ridge portion
in the shape of V in cross section.
[0031] The control unit may determine the presence or absence of
ink in the ink tank in accordance with the presence or absence of a
total reflection of light emitted from the light-emitting unit to
the window portion.
[0032] The device for detecting the presence or absence of a liquid
may be used as a device for determining whether the ink tank is
mounted on the carriage or not.
[0033] The recording means may use an electrothermal transducer for
generating thermal energy required for allowing a phenomenon of
film boiling to appear in ink in order to eject ink therefrom.
[0034] In a fourth aspect of the present invention, there is
provided a recording system, comprising:
[0035] an information processing unit for processing input
information;
[0036] an output unit for recording an output of the information
processing unit on a recording medium; and
[0037] a control unit for controlling an operating condition of the
output unit, wherein
[0038] the output unit having:
[0039] a carriage on which an ink tank having a window portion of a
light-transmitting material on at least one side surface thereof is
fixed or removably mounted;
[0040] a device for detecting the presence or absence of a liquid,
which are arranged in a position facing to the window portion of
the ink tank mounted on the carriage; and
[0041] a control unit for determining the presence or absence of
ink in accordance with the results obtained by the device for
detecting the presence or absence of a liquid.
[0042] In a fifth aspect of the present invention, there is
provided a kit comprising an ink tank, a recording means to be
connected with the ink tank, an ink refill means for refilling ink
into the ink tank, wherein
[0043] the ink tank is for supplying an ink to a recording means,
which is fixed on or removably mounted on a recording apparatus for
recording an input image information on a recording medium by using
the recording means that ejects ink, and comprises:
[0044] an ink-storing portion for storing ink, provided as an
ink-flow path for supplying ink to the recording means;
[0045] a front end portion on which an ink-supplying opening for
supplying the ink to the recording means;
[0046] a rear end portion formed on the other side of the ink tank
with respect to the front end portion;
[0047] a side surface portion on which a window portion made of a
light-transmitting material; and
[0048] other side source portions for surrounding the ink-storing
portion in conjunction with the side surface portion.
[0049] In a sixth aspect of the present invention, there is
provided a kit as claimed in claim 13, wherein
[0050] the recording means is an ink-jet recording head that uses
an electrothermal transducer for generating thermal energy required
for allowing a phenomenon of film boiling to appear in ink in order
to eject ink therefrom.
[0051] In a seventh aspect of the present invention, there is
provided a recording unit comprising an ink tank and a recording
means to be connected with the ink tank, wherein
[0052] the ink tank is for supplying an ink to a recording means,
which is fixed on or removably mounted on a recording apparatus for
recording an input image information on a recording medium by using
the recording means that ejects ink, and comprises:
[0053] an ink-storing portion for storing ink, provided as an
ink-flow path for supplying ink to the recording means;
[0054] a front end portion on which an ink-supplying opening for
supplying the ink to the recording means;
[0055] a rear end portion formed on the other side of the ink tank
with respect to the front end portion;
[0056] a side surface portion on which a window portion made of a
light-transmitting material; and
[0057] other side source portions for surrounding the ink-storing
portion in conjunction with the side surface portion.
[0058] The recording means may be an ink-jet recording head that
uses an electrothermal transducer for generating thermal energy
required for allowing a phenomenon of film boiling to appear in ink
in order to eject ink therefrom.
[0059] In an eighth aspect of the present invention, there is
provided a device for detecting the presence or absence of a
liquid, installed on an ink-jet recording apparatus on which a
recording head and an ink tank for supplying ink to the recording
head are fixed or removably mounted, comprising:
[0060] a window portion formed on at least a part of a wall of the
ink tank;
[0061] a light-emitting unit for emitting light to the window
portion; and
[0062] a light-receptor unit for receiving light which is reflected
off an inner wall surface of the window portion after emitting from
the light-emitting unit, wherein
[0063] a shape of the inner wall surface of the window portion is
different from a shape of an inner wall surface of the ink tank
around the window portion.
[0064] Here, the inner surface of the window portion may be shaped
so as to introduce light emitted from the light-emitting unit into
an interface between the ink and the ink tank at a predetermined
angle, and
[0065] the light-receptor unit is positioned on a path of light
reflected from the interface between the ink and the ink tank after
emitting from the light-emitting unit.
[0066] The light-emitting unit may be positioned so as to introduce
light into the window portion, perpendicularly.
[0067] The inner wall surface of the window portion may be shaped
so as to introduce incident light from the light-emitting unit into
the interface of the ink and the ink tank at an angle of 45.degree.
C.
[0068] In the following description, the term "recording" means
that all kinds of the procedure for proving ink on ink supports
such as cloth, yarn, paper, and other sheet materials (i.e.,
printing process, image-forming process, copying process, dye or
staining process, and the like). Therefore the field of the
invention is not limited to the field of information-processing,
and so it is also applicable to other fields including apparel
industries using the ink supports for receiving ink such as cloth,
yarn, paper, and other sheet materials.
[0069] The above and other objects, effects, features and
advantages of the present invention will become more apparent from
the following description of embodiments thereof taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0070] FIG. 1 is a schematic illustration of a conventional device
for detecting the presence or absence of a liquid in a
container;
[0071] FIG. 2 is a perspective illustration of a recording unit to
be mounted on an ink-jet recording apparatus in accordance with the
present invention;
[0072] FIG. 3 is a schematic illustration of a window portion of an
ink tank and a device for detecting the presence or absence of ink,
where the device comprises a light-emitting unit to emit light to
the window portion and a light-receiving unit to detect reflected
light;
[0073] FIG. 4 is a schematic illustration of a carriage and a
carriage-guide shaft for slidably supporting the carriage to be
applied in an ink-jet recording apparatus of the present invention,
where the carriage moves along the carriage-guide shaft in the
main-scanning direction;
[0074] FIG. 5 is a block diagram of electric circuit to be applied
in an ink-jet recording apparatus of the present invention;
[0075] FIG. 6 is a cross-sectional view of an ink tank and a device
for detecting the presence or absence of ink to be applied in an
ink-jet recording apparatus as one of the preferred embodiments of
the present invention;
[0076] FIG. 7 is a schematic cross-sectional view of an ink tank
and a device for detecting the presence or absence of ink to be
applied in an ink-jet recording apparatus as one of the preferred
embodiments of the present invention;
[0077] FIG. 8 is a schematic cross-sectional view of an ink tank
and a device for detecting the presence or absence of ink to be
applied in an ink-jet recording apparatus as one of the preferred
embodiments of the present invention;
[0078] FIG. 9 is a perspective illustration of a recording unit to
be mounted on an ink-jet recording apparatus as one of the
preferred embodiments of the present invention;
[0079] FIG. 10 is a schematic illustration of a carriage
configuration in which a recording unit having an ink-jet recording
head and an ink tank is mounted on the carriage;
[0080] FIG. 11 is a perspective diagram of an ink-jet recording
apparatus as one of the preferred embodiments of the present
invention;
[0081] FIG. 12 is a perspective diagram of an
information-processing system as one of the preferred embodiments
of the present invention; and
[0082] FIG. 13 is an ink-jet head kit comprising a recording head
unit and an ink refill device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0083] An ink tank as an ink-holding member to be mounted in a
recording apparatus according to the present invention, comprises
an ink-storing chamber, a front end portion in which an
ink-supplying portion is formed for supplying ink to a recording
means (hereinafter, also referred as a recording head) connected
therewith, a posterior end portion in which an air-communicating
port is formed to make a communication between the above
ink-holding means and the air, a side wall portion (hereinafter,
referred as an ink-flow path parallel to a direction of supplying
ink to the recording head, and a window made of a
light-transmitting material on a front end side of the side wall
portion. According to the present invention, furthermore, a device
for detecting the presence or absence of a liquid is installed in
the recording apparatus for detecting the presence or absence of
the remaining ink in the tank. Preferred embodiments of the present
invention will be described below in a concrete manner.
Embodiment 1
[0084] FIG. 2 is a perspective illustration of a recording unit to
be mounted on an ink-jet recording apparatus in accordance with the
present invention. The recording unit has a single-piece
construction in which an ink-jet recording head 20 is integral with
an ink tank 21 in a removable manner.
[0085] The ink-jet recording head 20 comprises an ink inlet portion
20a and an ink ejecting portion 20c communicated therewith. In this
embodiment, the ink-jet recording head 20 uses electro-thermal
conversion elements (hereinafter, referred as heaters) as
energy-generating means. Therefore a bubble is formed in ink of a
liquid pass by a pulse of an electric drive signal provided from
the system unit of the ink-jet recording apparatus, and in an
instant the growth and collapse of the bubble are occurred in a
suitable manner, resulting that it is particularly suited for an
ejection of ink-droplet because of a significant response
properties thereof. Thus, it is possible to make the ink-jet
recording head easily as compact as possible by using the
electro-thermal converting elements as the energy generating means.
Another advantage is that the recording head using the
electro-thermal conversion elements can be fully fabricated with a
process utilizing technical advances made in the semiconductor
fields in recent years and technical merits of IC and
microfabrication technologies with remarkable technical advances
and improved reliabilities, thus making high density fabrication
easy and reducing manufacture cost in addition to further
miniaturization of the recording head.
[0086] On the other hand, the ink tank 21 comprises an ink-holding
chamber 2 for reserving ink to be supplied to the ink-jet recording
head 20 and an opening as an ink outlet portion 21b formed on a
front end portion thereof into which an ink inlet portion 21a of
the ink-jet recording head 20 can be fitted. As shown in the
figure, there is a pair of projections 21d from the front end and
they have hooks on their free ends so as to be able to engage in a
pair of holes 20b formed on the end portion of the ink-jet
recording head 20 from which the ink-inlet portion 20b is
protruded. Furthermore, at least one side surface (i.e., an
ink-flow wall) 21c of the ink tank 21 is made of a transparent
material (e.g., transparent plastics and glasses), and also a
grooved portion is formed on the front side thereof. Or to put it
another way: the grooved portion is formed as a rise of an inner
side of the ink tank 21 so as to have a V-shaped cross section. In
this embodiment, therefore, the grooved portion is provided as a
window having two inclined surfaces 1a, 1b.
[0087] For illustrating the ink tank in brief, an ink-induction
member and an ink-absorbing member are not shown in the figure. In
this embodiment, however, it is not limited to such configuration.
It is also possible to provide other configurations of the ink tank
having such window, for example one having the ink-induction member
and the ink-absorbing member, or of separating the ink-holding
chamber into two parts (i.e., one for keeping these members and the
other for keeping ink). It is needless to say that the window may
be positioned in accordance the construction of the ink tank.
[0088] FIG. 3 is a schematic illustration of the window of the ink
tank shown in FIG. 2 and an ink-detecting assembly for detecting
the presence or absence of ink in the ink tank. The components that
make up the assembly include a photo-emitting member 10 for
illuminating light toward the window 1 of the ink tank 21 and a
photo-receptor member 11 for detecting reflected light.
[0089] The ink-detecting assembly can be positioned so as to face
to the above window 1 when it is mounted on a carriage of the
ink-jet recording apparatus (or a recording unit is positioned at a
home position thereof).
[0090] The photo-emitting member 10 is in the type of a high
directivity and generates a beam of light substantially without an
attenuation thereof in the ink. Thus the photo-emitting member 10
may be an illumination element having a light-gathering power by
means of a lens or the like with respect to infrared light or near
infrared light to illuminate a beam of light with a high
directivity. The beam of light emitted from the photo-emitting
member 10 is introduced into the inclined surface 1a at a
substantially constant angle .theta.in.
[0091] In this embodiment, by the way, the components of ink stored
in the ink tank 2 include glycol, alcohol, dye stuff, and the like
in addition to 80% or more of water. This kind of ink has a
refractive index n-ink of 1.3 to 1.4, almost the same order as that
of water. On the other hand, the wall of ink-flow path may be made
of a transparent plastic or grass material, having a refractive
index n-wall of 1.5 to 1.6. In addition, the air has a refractive
index n-air of approximately 1.0003. Therefore, in the case that a
substantial amount of ink is found in the ink flow path, a critical
angle .theta.1 to cause a total reflection against the incident
light at the inclined surface 1a can be calculated by the following
formula (1) and results in the critical angle .theta.1 of 54 to 69.
sin(.theta.1)=n-ink/n-wall (1.5.about.1.6)/(1.3.about.1.4) (1)
[0092] In the case of the absence of ink in the ink flow path, a
critical angle .theta.2 to cause a total reflection against the
incident light at the inclined surface 1a can be calculated by the
following formula (1) and results in the critical angle .theta.2 of
39 to 42. sin(.theta.2)=n-air/n-wall=1.003/(1.5-1.6) (2)
[0093] In the case that the incident angle .theta.in to the
inclined surface 1a is in the range of 43 to 53, consequently, a
total reflection cannot be occurred in the presence of ink while it
can be occurred in the absence of ink. Thus the present embodiment
is configured to define the incident angle .theta.in=45.degree..
Accordingly, in the case that a substantial amount of the ink is
present in the tank the incident light passes through the ink-path
wall 1 and travels along a light path 3. In the case that a
substantial amount of the ink is not present in the tank, on the
other hand, the incident light does not pass through the ink-path
wall 1, while it is reflected from the inclined surface 1a and
travels along a light path 4. Then the light passing through the
light path 4 is total-reflected by the inclined surface 1b and then
travels along the light path 5 extending to the photo-receptor
member 11.
[0094] The presence or absence of ink in the ink path 2 can be
detected with stability according to the relationship among the
light intensities indicated by the following inequality:
A>B>C wherein A represents an intensity of the light detected
by the photo-receptor member 11 when the ink is not present in the
ink path, B represents an intensity of the light detected by the
photo-receptor member 11 when the ink is present in the ink path,
and C represents an intensity of the light detected by the
photo-receptor member 11 when the ink path is not found (i.e., the
ink tank is not mounted on the carriage). The difference between A
and B is comparatively large, so that the presence or absence of
ink in the ink path 2 can be detected with stability by the
differences among the light-intensities of the light introduced
into the photo-receptor portion 11. In this case, by the way, the
difference between B and C is comparatively small. However, the
detection of the presence or absence of ink in the ink tank can be
performed by improving the detection-sensitivities of the
photo-receptor 11.
[0095] In the figure, "h" represents a height of an ink surface at
the position lower than the tip 1c of the V-shaped portion formed
on the window 1, where the light beam from the photo-emitting
member 10 comes into contact with the inclined surface 1a. A total
reflection of the light beam can be occurred when the ink surface
is lower than h by consuming the ink, so that h is responsible for
determining a detection point for regarding the ink-path (or the
ink tank) as empty whether a small amount of ink is being remained
or not. Therefore it is possible to change the above height h by
shifting the position of the photo-emitting portion 10 to shift a
point on which the light beam from the photo-emitting portion 10
comes contact with the inclined surface 1a.
[0096] In the figure, reference numeral 12 is a douser for
preventing the incident of light from the photo-emitting portion 10
to the photo-receptor portion 11, by which the reflected beam can
be detected with stability when the photo-emitting portion 10
consists of a cheep photo-emitting element such as a light-emitting
diode (LED). For improving the straight-traveling properties of
light, furthermore, the light emitted from the light-emitting
member 10 may be introduced into the ink-flow path 2 after passing
through a slit (not shown) to travel in a straight line. A
hydrophilic treatment may be performed on the ink-flow wall for
preventing a deposition of bubbles thereon with effect.
[0097] By the way, the present invention is configured to utilize a
refractive index of the ink, so that the results of the detection
described above is hardly susceptible to the variations in colors
of ink. It means that the above means for detecting the presence or
absence of ink in the ink path can be utilized in a color printer
or the like, with respect to all of different colors used
therein.
[0098] FIG. 4 is a schematic illustration of a carriage 22 and a
carriage-guiding axis 23. As described above, the recording unit
has a single-piece construction in which an ink-jet recording head
20 is integral with an ink tank 21 in a removable manner. The
carriage-guiding axis 23 is responsible to hold the carriage in a
slidable manner, on which the carriage moves in the sub-scanning
direction.
[0099] The ink-jet recording head 20 has a positioning portion (not
shown) and a flexible base board (electric connecting portion) for
electrically connecting to the carriage 22. By using such devices,
therefore, the ink-jet recording head 20 can be mounted on the
carriage 22 with an electric connection therebetween.
[0100] An electric circuit of the ink-jet recording apparatus is
constructed as described in the follows and shown in a block
diagram of FIG. 5. In the figure, the same components as
illustrated in the other figures are indicated by the same
reference numerals, and also their duplicated explanations are
eliminated in the following description. In the figure,
furthermore, reference numeral 401 denotes a controller as a main
control unit, 402 denotes, a central processing unit (CPU) in the
shape of one used in, for example a micro-computer, 403 denotes a
random access memory (RAM) having a region for expanding text data
or image data, a work region, and so on, 404 denotes a read only
memory (ROM) in which stationary data such as program data and font
data are stored, 405 denotes a timer responsible for making
execution cycles of the CPU 402 and for producing timings to be
required in a recording movement by the printer unit, and 406
denotes an interface portion for connecting signals of the CPU 402
with the peripheral devices. Furthermore, reference numeral 407
denotes a controller of the printer unit 407, and 11 denotes a
light-receptor unit shown in FIG. 2. Reference numeral 408 denotes
an ink tank sensor for making sure the presence or absence of the
ink tank, 409 denotes a head driver for sending recording signals,
electric powers, and so on to the ink-jet recording head 20, 410a,
b, and c denote motor drivers for sending signals, electric powers,
and so on to be required for motors of moving the carriage, feeding
the recording paper, driving the recovering system, and so on,
respectively, 411 denotes a carriage sensor for detecting a
location of the carriage and determining, for example whether the
carriage is located at a home position or not, 412 denotes a paper
sensor for detecting the presence or absence of a sheet of paper to
avoid a recording on non-recording areas thereof or other
components when the recording paper is not appropriately provided
or when a last sheet of paper is recorded.
[0101] In the configuration described above, a warning against the
remaining quantity is performed if the ink detecting unit detects
the absence of ink in the ink tank. In this case, the remaining
quantity of ink in the ink tank can be estimated almost accurately
at the time of detecting the absence of ink in the ink tank (i.e.,
at the time of warning against the remaining quantity) because the
detecting means comes to a conclusion that the ink is absent when
the ink surface is under the predetermined ink level. Therefore, it
may be configured so as to output an ink-less error after
determining that the amount of ink consumed is reached at the
predetermined level by calculating the consumption of ink at the
events of recording, primary ejection, absorption, and the like
which are performed after the output of ink-less error.
Furthermore, it may be also configured so as to inhibit the
movements of recording, absorbing, and the like after the output of
ink-less error. The data concerned with the remaining quantity of
the ink is stored in the RAM 402 described above, and so it is
preferable that the RAM 402 is in the type of nonvolatile.
Embodiment 2
[0102] FIG. 6 is a schematic section view of an ink tank and an
ink-detecting unit of the ink-jet recording apparatus as a second
preferred embodiment of the present invention. An ink-flow wall 501
has a plurality of inclined surfaces 501a formed as a sawtooth in
cross section. Therefore, it is configured to perform a stable
detection of total reflected light or transmitted light depended on
the presence or absence of ink at the inclined surfaces 501a in the
event that the light emitted from the light-emitting unit 510 is
diffused to an extent: The light emitted from the light-emitting
unit 510 is introduced into a plurality of the inclined surfaces
501a. If the ink is in the ink-flow path 502, the light passes
through the inclined surfaces 501a and then travels along a light
path 503. If the ink-flow path 502 holds no ink but the air, the
inclined surfaces 501a reflect the light perfectly and the
reflected light travels along a light path 504. By the construction
shown in FIG. 6, furthermore, it is possible to change the height
of the inclined surfaces 501a to meet the user's needs. In
addition, there is no possibility of generating any irregular of
the light reflection to be caused by a scratch on an inclined
portion because a plurality of the inclined surfaces 502 is formed
in an inner side of the ink tank.
Embodiment 3
[0103] FIG. 7 is a schematic section view of an ink tank and an
ink-detecting unit of the ink-jet recording apparatus as a third
preferred embodiment of the present invention. An inclined surface
61a is formed on a corner (at a front-end side) of an ink-flow wall
601, so that an ink tank can be provided as of a simple shape so as
to have a high degree of flexibility in formation of the inclined
surface at an appropriate portion.
Embodiment 4
[0104] FIG. 8 is a schematic section view of an ink tank and an
ink-detecting unit of the ink-jet recording apparatus as another
preferred embodiment of the present invention. Inclined surfaces
701a, 701b are formed on the other side of the ink-flow wall 701
with respect to the ink-flow path 702. A light-emitting unit 710 is
positioned so that the inclined surface 701a is almost
perpendicular to the incident light, i.e., the light emitted from
the light-emitting unit 710 enters into the inclined surface 701a,
almost perpendicularly. On the other hand, a light-receptor unit
711 is positioned so that the inclined surface 701b is on a path of
the total reflected light. In this case, there is no need to
provide the inclined surface 701b as a plane perpendicular to the
light path, but a detection without an influence of the reflection
index of the light can be performed more stable as the relationship
between the light path and the inclined surface 701b get closer to
a right angle.
Embodiment 5
[0105] FIG. 9 is a schematic section view of an ink-jet unit to be
mounted on the ink-jet recording apparatus as another preferred
embodiment of the present invention.
[0106] The inclined surfaces 801a, 801b are formed on a side
surface of an ink tank 821. In addition, a light-reflective portion
810 is also formed on the same side surface.
[0107] FIG. 10 is a schematic illustration of a carriage on which
the ink-jet unit having the ink-jet recording head and the ink tank
shown in FIG. 9 is mounted. In the figure, reference numeral 810
denotes a photosensor unit as a combination of light-emitting
portion and a light-receptor portion. The photosensor 810 is
installed on a fixed portion formed on an outside of the carriage
822. When the carriage 822 travels along the carriage guide axis
823, the inclined surfaces 801a, 801b of the ink tank 821 and the
light-reflective portion 801c face to the photosensor portion 810,
respectively, according to the shifted positions of the carriage
822. Therefore, the absence or presence of the ink can be detected
by facing the photosensor portion 810 to the inclined surfaces
801a, 801b, while the absence or presence of the ink tank on the
carriage can be detected by facing the photosensor portion 810 to
the light-reflective portion 801c. It means that the absence or
presence of the ink and the absence or presence of the ink tank are
detected by using only one common photoreceptor By forming each
surface of the ink tank as impenetrable by light except the
inclined surfaces 801a, 801b, the light passes only through the
inclined surfaces 801a, 801b. When the inclined surfaces 801a, 801b
are covered with the ink (i.e., the ink level is higher than their
positions), they do not reflect the incident light and so an inner
side of the ink tank can be seen as a dark place by making visual
observations through the surfaces 801a, 801b. When the inclined
surfaces 801a, 801b are clear of the ink (i.e., the ink level is
lower than their positions), they reflect the incident light and so
an inner side of the ink tank can be seen as a light place by
making visual observations through/the surfaces 801a, 801b.
Consequently, the absence or presence of the ink in the ink tank
can be determined by observing those conditions. In the case that
the incident light should be cut off from the ink tank, the absence
or presence of the ink can be also detected by observing through
the inclined surfaces.
Other Embodiments
[0108] A general construction of the ink-jet recording apparatus on
which the ink tank and the ink detecting unit of one of the above
embodiments 1 to 5 are mounted will be described below with
reference to FIG. 11.
[0109] FIG. 11 is a schematic illustration of an ink-jet recording
apparatus as one of the preferred embodiments of the present
invention.
[0110] An ink-jet recording apparatus IJRA has a lead screw 2040
that rotates by working together with a normal or reverse rotation
of a driving motor 2010 through a set of transmission gears 2020,
2030. A carriage HC on which an ink-jet cartridge is mounted is
supported by a carriage shaft 2050 and the lead screw 2040. Also,
the carriage has a pin (not shown) to be engaged in a spiral groove
2041 formed on a peripheral surface of the lead screw 2040 so as to
move back and forth in the directions shown by the arrows a, b.
[0111] Reference numeral 2060 denotes a platen plate that positions
the paper P and holds it against a platen roller 2070 in the
direction of moving the carriage. Reference numeral 2080 and 2090
are photocouplers to be used as a home-position detecting means for
changing a rotational direction of the motor 2010, and so on by
recognizing that a lever 2100 arranged on the carriage HC is
located at the position of these photocouplers.
[0112] A head recovering unit comprising a capping member 2110 and
a sucking member 2130 is arranged at the position facing to one end
of the path of displacement of the carriage HC, e.g., the position
located opposite to a home position of the ink-jet cartridge IJC.
As the driving force generated by the motor 2010 is transmitted via
the power transmitting gears 2020, 2030, the head recovering unit
is activated to cap the recording head with the cap member 2110
supported by a supporting member 2120. Subsequently, ink is sucked
(to attain suction recovery) by driving the sucking member (e.g.,
suction pump) 2130 disposed in the head recovering unit in
operative association with the capping member 2110, whereby ink
located in the ink ejecting ports of the recording head with
increased viscosity is forcibly discharged from the ink ejecting
ports.
[0113] Reference numeral 2140 designates a cleaning blade for
wiping an ejection surface of the recording head and it is held by
a blade holding member 2160 so as to move back and forth. These
members are arranged on a supporting plate 2160 of a main body.
[0114] Reference numeral 2170 designates a lever for starting a
suction recovery. The lever 2170 moves with a movement of cam
engaged with the carriage HC to control a driving force of the
motor 2010 by producing variable or reciprocating motion in parts
of transmission mechanism such as a clutch shifter.
[0115] Since a recording apparatus including an ink-jet recording
head of the foregoing type makes it possible to perform a recording
operation not only at a high density but also at a high speed, it
is utilized and commercialized as outputting means for a recording
system, e.g., a printer serving as an output terminal unit for a
copying machine, a facsimile, an electronic typewriter, a word
processor, a work station or the like or a handy or portable type
printer to be equipped in an information processing system such as
a personal computer, a host computer, an optical disc unit, a video
unit or the like. In the circumstances as mentioned above, an
ink-jet recording apparatus is constructed in such a manner as to
match with a function and a type of practical use inherent to each
of the aforementioned units.
[0116] In the case of a color ink-jet recording apparatus for
printing in two or more colors, a multicolor image is formed by
allowing ink droplets to overlap one above another on a recording
medium by ejecting inks of several colors from a plurality of color
ink-jet recording heads or by an arrangement of colors into rows
and columns of a matrix (N.times.N) on the recording medium.
Generally, in the case that a color recording operation is
performed with the color ink-jet recording apparatus, three or four
ink-jet recording heads and three or four ink cartridges
corresponding to three primary colors composed of yellow (Y),
magenta (M) and cyan (C) or four colors composed of three primary
colors and black (B). Lately, a color ink-jet recording apparatus
having three or four kinds of color ink-jet recording heads mounted
thereon so as to enable an image to be formed with full color has
been put in practical use.
[0117] In addition, the foregoing type of color ink-jet recording
apparatus can be constructed in such a manner as to enable an image
to be comparatively easily recorded on a recording medium with a
size of "A-1". Concretely, a color ink-jet recording apparatus
electrically connected to a reader adapted to read a A-1 sized
original of multicolor image so as to allow the original to be
recorded on a recording paper, e.g., a plotter serving as a CAD
output printer has been commercialized. On the other hand, it is
practically required that the color ink-jet recording apparatus can
be used in a variety of fashions, and lately, requests have been
increasingly raised from users for providing a color ink-jet
recording apparatus capable of recording various kinds of
information such as characters, graphs, pictures, and figures on an
OHP film in order to visually project the information on a screen
for the presentation in a conference or lecture.
[0118] We are now explaining a recording system that performs a
recording on a recording medium by using a liquid-ejecting head as
a recording head.
[0119] FIG. 12 is a schematic illustration of the recording system
as a preferred embodiment of the present invention. In this
embodiment, a liquid-ejection head is of a full-line type with a
length thereof corresponding to a recording width of the recording
medium 150. The liquid-ejection head comprises a plurality of
orifices with pitches of 360 dpi in the direction of length. In the
liquid-ejection head, there is a holder 202 for folding four heads
corresponding to four different colors: yellow (Y), magenta (M),
cyan (C), and black (Bk), respectively. These color heads are
arranged in parallel with predetermined spacing in the direction of
arrow X.
[0120] Each of these color heads receives signals from a head
driver 307 comprised in the driving signal supplying means, and
thus they are driven according to their corresponding signals,
respectively. In addition, the color heads receive color ink of Y,
M, C, and Bk from ink tanks 204a-204d, respectively.
[0121] Furthermore, reference numeral 204e denotes a container for
storing a blowing solution, so that each of the color heads is
configured to receive a supply of the blowing solution from the
container 204e. In this embodiment, these ink tanks 204a-204d and
the container 204e have window portions (not shown) as the same as
any one of the above embodiments 1 to 5. The window portion of each
tank or container is arranged so as to face to a corresponding
device for determining the absence or presence of a liquid.
[0122] Head caps 203a-203d, in which ink-absorbing materials such
as sponges are imbedded, are arranged below the color heads,
respectively, for their protection by covering each head with each
corresponding head cap at the period of non-recording.
[0123] Reference numeral 206 denotes a feed belt as a means for
transmitting the recording material. The feed belt is routed round
various kinds of rollers in a predetermined path and driven by a
drive roller connected with a motor driver 305.
[0124] In the recording system of the present embodiment, various
kinds of treatments can be down on the recording medium, before and
after the recording. Thus the recording system comprises a
pre-treatment device 251 for treating the recording medium prior to
the step of recording and a post-treatment device 252 for treating
the recording medium subsequent to the step of recording. The
pre-treatment device 251 is arranged in the downstream of a path of
feeding the recording medium, while the post-treatment device 252
is arranged in the upstream thereof.
[0125] The contents of the pre- and post-treatments are varied
according to the variations of ink or recording media to be used
for the recording process, for example the application of UV and
ozone is performed on a recording medium made of metal, plastic,
ceramic, or the like to activate a surface thereof for improving
the adherence. In the case of using a recording medium having a
static-prone surface, such as a sheet of plastic material, debris
may be easily to adhere thereon to prevent the formation of an
excellent image by the contaminated surface. The recording medium
may be guarded against static buildup with an ionizer as the
pre-treatment to remove the debris from the recording medium. In
the case of using a textile- or fabric-based recording medium, it
is preferable to perform a pre-treatment of one selected from the
group of alkaline materials, water-soluble materials, synthetic
polymers, water-soluble metallic salts, urea, and thiourea from the
points of, for example preventing shrinkage and improving the
degree of exhaustion. It is noted that the pre-treatment procedures
are not restricted by the above ways. It is also possible to adopt
other procedures, for example a pre-treatment having the step of
heating the recording medium at a temperature preferable to the
recording.
[0126] For the post-treatment, on the other hand, there are several
treatments can be performed, for example: a fixation for fixing ink
applied on the recording medium by means of UV irradiation or by
means of heat; and a washing fro removing a remaining unreact
material used in the pre-treatment.
[0127] Accordingly, the ink-jet recording apparatus of the present
invention can be used as one superior to the others in many
industrial fields (e.g., apparel industries) and provides images
with excellent image qualities compared with that of the
conventional one.
[0128] By the way, as described above, the ink tank can be
removably connected with the ink-jet recording head to form a
recording unit in a one-piece design. Thus it can be introduced in
the market. In accordance with the present invention, therefore it
is also possible to provide an ink refill means for replenishing
the ink tank with ink.
[0129] FIG. 13 is a schematic illustration of an ink-jet head kit
provided as a set of a recording unit and an ink refill device.
That is, a kit container 501 comprises an ink-jet recording head
510 having an ink ejection portion 511 for ejecting ink, an ink
tank 520 as a liquid container which is stationary or removably
connected with the ink head 510, and an ink refill device 530 for
refilling ink into the ink tank 510.
[0130] After using the ink up, ink may be refilled in the ink tank
through an insert portion (e.g., injection needle) 531 of the ink
refill device. That is, the insert portion 531 of the ink refill
device is inserted into a hole made on a wall or an air
communicating port 521 of the ink tank, or a connected portion
between the ink tank and the recording head.
[0131] In accordance with the present invention, as described
above, the ink-jet kit combines the ink-jet recording head, the ink
tank having the configuration of one of the above embodiments, and
the ink refill device into a container of compact design. In the
case of using the ink up, therefore, the recording can be easily
carried out again without much times by refilling ink into the ink
tank by using the above kit.
[0132] As explained above, the device for detecting the presence or
absence of a liquid, ink tank, kit, recording unit, recording
apparatus, and recording system constructed by the connection with
the information processing device of the present invention are
configured to determine the presence or absence of ink in the ink
flow path by detecting the reflection of light from a light
transmission portion by irradiating light thereon. The light
transmission portion is formed on at least a part of the ink path
wall that forms the ink flow path for supplying ink to the
recording head. As a result, it becomes possible for responding to
consumer demands of designing a smaller version of the ink tank, a
cost effective production thereof, and the like in addition to
provide images with excellent image qualities.
[0133] The present invention has been described in detail with
respect to preferred embodiments, and it will now be apparent from
the foregoing to those skilled in the art that changes and
modifications may be made without departing from the invention in
its broader aspects, and it is the intention, therefore, in the
appended claims to cover all such changes and modifications as fall
within the true spirit of the invention.
* * * * *